The present invention relates generally to solar energy recovery systems and more specifically to solar energy recovery systems employing a solar tracking system to increase the operating efficiency of an associated solar energy generating unit.
In recent years a great deal of attention has been focused on the use of solar energy as a safe and clean alternative to the use of energy provided by fossil fuels and other means. Radiant energy from the sun may be converted to a useful energy form such as electricity or longer wave length heat radiation by a solar collector. A solar collector typically consists of an open or transparent face of admitting solar radiation and internal structure for receiving and transforming the radiation to useful energy.
In order for the solar collector to receive a maximum energy input it must be continuously directed toward the sun and thus is operated most efficiently when equipped with a device designed to track the sun as it travels across the sky.
Many types of tracking devices have been provided to accomplish this function. For example, some devices consist merely of a time actuated servo-motor which moves the solar collector through an arc about a fixed axis. However, problems are encountered due to the fact that the physical points of sunrise and sunset on the horizon and the times thereof, vary nonlinearlly throughout the year.
Tracking systems with photo electric sun sensing devices have also been used. These devices generally overcome problems associated with the transient and nonlinear nature of the sun's path, but encounter problems with the reduced sunlight conditions caused by clouds and the like. Such systems must generally be directed toward the point of sunrise to begin the tracking function and return to this orientation when the sky becomes sufficiently dark at dusk. However, clouds may create a lighted condition similar to dusk thereby causing the unit to return to the easterly starting orientation where it remains until reactivated the next morning. In more sophisticated models the unit may pivot between the sunrise position and the sun oriented position in response to the passage of a dark cloud. Both conditions cause loss of sun time and waste energy in the needless operation of the servo-motor. Thus a need exists for a solar tracking system capable of overcoming these problems.
A self adjusting solar energy unit might be particularly useful in ranching and similar operations where there is often a need for an electricity generating unit in a remote or inaccessible area which is not serviced by utility lines. Pumping well water to a stock tank in a remote area is a typical problem. A solar energy generating unit capable of powering a pump motor might be used to overcome such problems. Such a unit should be self operating and should be provided with a sun tracking for obtaining maximum efficiency from the solar energy generating unit.